Part 5: Philosophy of Science: Demarcation

1.
AN INTRODUCTIONTO
PHILOSOPHY OF SCIENCE
PART 5
John Ostrowick
john@ostrowick.com

2.
SO FAR…
• So far…
• In part 1, we saw how formal logic works
• We’ve seen some fallacies.
• We’ve seen the difference between induction, deduction and abduction.
• In part 2, we identiﬁed that induction is fallacious (logically)
• We saw that there’s a problem of induction which says that we can’t generalise
(past to future, token to type, etc)
• Yet science generalises.

3.
SO FAR…
• So far…
• We saw that we can instead argue that science uses probability claims
• We saw how Bayes’Theorem works
• And we saw some problems with it, like how to ﬁx the prior probabilities.
• We saw that we can ﬁx the priors with frequentism or propensity.
• We saw that background knowledge can inﬂuence believability.
• We saw that there’s a problem with deciding what evidence is relevant.

4.
SO FAR…
• So far…
• Then, in part 3, we saw how science tries to explain
observations.We saw that
• There’s a problem with the notion of causation
• That we need to distinguish causation and correlation
• There’s a question of curve-ﬁtting, simplicity, predicting evidence,
theoretical ﬁt, and extrapolation

5.
SO FAR…
• So far…
• Then we saw the problem of underdetermination of
theory by evidence and
• Occam’s Razor and Simplicity and
• Other measures of a good explanation and
• The problem of theory-laden observations.

6.
SO FAR…
• So far…
• In part 4, we saw the realism vs instrumentalism debate:
• That realism is the view that science is ﬁnding truth
• That the No Miracles Argument says science wouldn’t be
successful if it wasn’t ﬁnding truths
• And thatVerisimilitude says that science is ﬁnding something “like”
truth, and it’s getting better all the time.

7.
SO FAR…
• So far…
• But then we saw that instrumentalism is the view that science ought to be
pragmatic and stick to producing useful formulas, etc., not ‘truth’,
• That we have paradigm shifts and so science is never ﬁxed,
• That there may be hidden variables that explain anomalous sciences that
seem detached from the familiar operations of the physical world, and
therefore, that realism might be rescued, and lastly
• That realism can be used to impose a ‘scientiﬁc’ perspective on other cultures.

8.
INTRODUCTION
• In this part, we ask: What is
science?
• In this ﬁnal part, we discuss how
science is demarcated from non-
science and pseudo-science, and
• What practical problems may arise
from science.

9.
THE DEMARCATION PROBLEM
• What is science and why do we care?
• If science is successful, and other disciplines and
research areas want to partake in that success, they
ought to imitate the scientiﬁc method, so as to get
the same levels of success.
• We also want to be able to tell inductively bad
arguments from inductively good arguments.
• We want to be able to decide what is “expert
testimony” in a court, e.g. from a psychiatrist or
ballistics expert, as opposed to a layperson’s opinion.

10.
THE DEMARCATION PROBLEM
• So what is science?
• So what makes a claim or theory scientiﬁc? Is it because it is a
claim about the physical world? If so, some forms of
psychology, and string theory, might not be science.
• Or is it a claim about what is known to be true? If so,
quantum mechanics isn’t scientiﬁc, because we can’t give true
ﬁnal statements about electrons’ energies or velocities or
momenta or positions, all at the same time.

13.
THE DEMARCATION PROBLEM
• Scientiﬁc Attitude
• Merton for example, identiﬁes the scientiﬁc attitude as being
one of universalism, communality, disinterestedness or
objectivity, and organised skepticism.
• But it speaks more to what a scientist is, than what makes a
scientiﬁc theory scientiﬁc. Perhaps the best we can draw
from this is that science is any theory that is objective or
free from cultural particulars, and which is the result of
skeptical inquiry. However, it is unclear whether anyone
can be culturally neutral in all cases.

14.
THE DEMARCATION PROBLEM
• Demarcation of science
• Here are some possible criteria to demarcate
science.
• We discuss each in turn.

15.
THE DEMARCATION PROBLEM
• Demarcation of science
• It deals with empirical phenomena (as opposed, say, to spiritual phenomena)
• It measures the physical world objectively
and conducts experiments
• It proposes theories to explain those
phenomena
• It is based on mathematics
• It has “laws” which describe how the
universe works

16.
THE DEMARCATION PROBLEM
• Demarcation of science
• Its success rate is high (its predictions almost always work)
• It is revisable, and its theories change or adjust as new information comes in;
fallibilism, in short, is a marker of science
• Its theories are testable
• It may be said to be inductive
• It provides epistemic warrant
• It is timelessly useful or true

17.
THE DEMARCATION PROBLEM
• Demarcation of science
• Each of these have some problems.

18.
THE DEMARCATION PROBLEM
• Demarcation of science
• It deals with empirical phenomena. Not only - we can investigate anything. E.g.
spirituality in the brain.
• It measures the physical world objectively (as opposed to subjectively) and
conducts experiments. Ideally, yes, in practice, objectivity is difﬁcult.
• It proposes theories to explain those phenomena. No, theology has theories.
• It is based on mathematics. Not all. E.g. Evolution (originally), tectonics.
• It has “laws” which describe how the universe works. Other disciplines, e.g. astrology,
claim to have laws.

19.
THE DEMARCATION PROBLEM
• Demarcation of science
• Its success rate is high. Trouble is, discarded theories were once considered ‘successful’.
• It is revisable, and its theories change or adjust as new information comes in;
fallibilism, in short, is a marker of science. This is a key claim, supported by Popper.
• Its theories are testable. This is mostly correct, except String Theory*
• It may be said to be inductive. Hempel disagrees.
• It provides epistemic warrant. Perhaps, but the instrumentalists disagree.
• It is timelessly useful or true. This is false; what is now science may later be nonsense.

21.
THE DEMARCATION PROBLEM
• Newton-Smith
• Verisimilitude.We’ve already seen problems with that.Also, philosophy is verisimilitudinal.
• 1. Observational nesting refers to “replicating the observational successes of another
theory as well as improving on them” (ibid). However, some theories make predictions of
new observations that would otherwise have not been expected or even noticed, such as
gravitational lensing and StringTheory, and they’re not really Newtonian or Quantum
Mech.s.
• 2. Fertility. It is true that scientiﬁc theories yield further scientiﬁc theories. So, Newton’s
laws of motion ultimately led to Einstein’s Relativity; Bohr’s model of the atom ultimately
led to Quantum Mechanics, and so on. However, fecundity is not the sole preserve of
science. E.g.Aquinas and Catholicism.*

22.
THE DEMARCATION PROBLEM
• Newton-Smith
• 3. Track record.Whether something has thus far proven a good theory is
no sign that it is in fact a scientiﬁc theory or a good theory, especially if it is
irrefutable.Theism, for example.
• 4. Inter-theory support with existing theory.This criterion is correct. So,
for example, Le Châtelier’s theory works well within the context of
thermodynamics and chemistry. However, a theory can ﬁt in well with
existing theory and still be false (think of Bohr’s atom), and there can be
non-scientiﬁc systems of thought with coherent theoretical models (think of
astrology and theism here).

23.
THE DEMARCATION PROBLEM
• Newton-Smith
• 5. Smoothness. If a theory responds well to changes, this is I believe a
good marker of a theory being scientiﬁc.
• 6. Internal consistency.This is similar to (4) above and takes the
same considerations.Theism is consistent. If we consider the sciences
as a whole. Biology is coherent with chemistry, and chemistry is
coherent with particle physics. However, this raises the question of
what theory was the ﬁrst scientiﬁc theory, if a pre-existing scientiﬁc
theory is required to demarcate a new theory as scientiﬁc.

24.
THE DEMARCATION PROBLEM
• Newton-Smith
• 7. Compatibility with well-grounded metaphysical beliefs.This one, like
consistency above (4), is problematic. It also begs a question of which
metaphysical beliefs are well-grounded. So, theism is well-grounded, if one
considers the vast literature supporting it.Also, which beliefs were the ﬁrst
well-grounded ones?
• 8. Is simple. Swinburne (2004) argues that theism is simple.And we’ve seen
the debate about what “simple” means. Quantum mechanics isn’t ‘simple’.
• Are these criteria necessary, sufﬁcient, or jointly necessary and sufﬁcient?

25.
THE DEMARCATION PROBLEM
• Popper
• Science is about “conjectures and refutations”.
*
• “Statements or systems of statements, in order to
be ranked as scientiﬁc, must be capable of
conﬂicting with possible, or conceivable
observations” (Popper 1962, p39).
• “A sentence (or a theory) is empirical-scientiﬁc if
and only if it is falsiﬁable”. (Popper, 1989, p82).

26.
THE DEMARCATION PROBLEM
• Popper
• Criticisms
• Consider the case of the irregular orbit of Uranus. It didn’t follow the
normal elliptical orbit, but had an aberration.This did not mean that, now
that we’d found counter-evidence to the claim that planets’ orbits trace out
ellipses.
• Likewise for the precession of Mercury, where existing Newtonian
mechanics saw it losing degrees of arc as it travelled around the sun. Instead
of discarding existing astronomy, we adopted Einstein’s modiﬁcations.

27.
THE DEMARCATION PROBLEM
• Popper
• Criticisms
• Scientists don’t act as if they’re proposing a theory and trying to refute it.
Generally, they’re seeking evidence to support it, or, they’re inferring a theory
from “neutral” observations.
• Popper’s falsiﬁcation generally doesn’t happen in what Kuhn calls ‘normal science’,
where people operate within existing theories.That being said, it means that
‘normal science’, e.g. work done in a chemistry lab, is not science (because
nothing is being falsiﬁed), and only revolutionary science, e.g. when a theory is
overthrown, such as Einstein’s case — only that, is science.

28.
THE DEMARCATION PROBLEM
• Popper
• Criticisms
• Lakatos argues that if Popper is right, we can get non-scientiﬁc theories that are
scientiﬁc, and scientiﬁc theories that are non-scientiﬁc. (Lakatos 1981, p117).
• So, for example, if StringTheory cannot be falsiﬁed, it is unscientiﬁc, whereas if
Astrology can be falsiﬁed, it is scientiﬁc.
• Lakatos, instead, argues that progress in science is made when theories
make surprising predictions that are conﬁrmed, and the ‘content’ of the
theory is increased.

29.
THE DEMARCATION PROBLEM
• Hempel
• Hempel proposed what is known as the deductive-
nomological (DN or D-N) model.
• What makes science different is that science
postulates a hypothesis (or law), and, from that law,
which is usually expressed mathematically, we can
deduce (or predict) what events or data will occur
when we measure.Thus, we deduce (predict) from
the law (nomos, in Greek). Not inductive

30.
THE DEMARCATION PROBLEM
• Hempel
• Hempel’s motivation for proposing DN seems to be about
‘expectability’ of events, given determinism and causation, that
is, that unless we have a deterministic explanation for
something, it is not explained.
• Laws of optics entail that light will refract in a certain way* ;
we can deduce the position of planets given Kepler’s laws,
Newton’s laws, etc.*

31.
THE DEMARCATION PROBLEM
• Hempel
• Criticisms
• For “normal science”, say, where we are conﬁrming Newton’s laws
of motion, he seems to be correct.
• However, in the case of new science, where we are going to
propose a new theory, it is less clear that we’re using the DN model.
General Relativity, say. You can’t deduce out of non-existing laws.

32.
THE DEMARCATION PROBLEM
• Hempel
• Criticisms
• Consider again the case of Boyle’s Law. It was ﬁrst observational, and
wasn’t based on existing law.
• Secondly, it’s hard to say how a scientiﬁc law differs from a true
contingent generalisation, such as “all presidents of USA are and have
been men”. If D-N is correct, we could deduce that all future presidents
would be men. Hempel takes them to be ‘exceptionless generalisations’
but we can think of many such cases which we don’t want to call laws.

33.
THE DEMARCATION PROBLEM
• Hempel
• Criticisms
• Third, it seems to require determinism, which means that chaotic and
quantum-random events may not be well-explained by laws. Meteorology,
economics, Brownian Motion, ﬂuid ﬂow turbulence, and so on would be
unscientiﬁc.
• But Hempel does recognise “inductive statistical” IS explanations.
However, it’s unclear whether this is compatible with DN or a necessary or
sufﬁcient condition for scienciness.

34.
THE DEMARCATION PROBLEM
• Hempel
• Criticisms
• Explanatory asymmetries may arise. So, we can
perhaps explain a phenomenon by reference to laws
and initial conditions, but the laws themselves remain
unexplained, and we can’t deduce the laws from the
observations. Boyle again.

35.
ETHICS AND SCIENCE
Technology or Theory Reason it exists Beneﬁt Problem
Nuclear Power Einstein’s theory of relativity
and atomic physics led to it.
Nuclear power stations
generate little waste compared
to the amount of energy they
produce
Radioactive waste
Nuclear weapons of mass
destruction; over 60 000
people killed in each bombing
Eugenics and Racialism Scientiﬁc studies of
phenotypes in the 19th
century created theory of
racialism (races are real
biological phenomena)
Purportedly to understand
human origins
Racism justiﬁed by science on
spurious evidence
Supported Nazi doctrine
GMOs and Genetic Modiﬁcation:
Designer Genes
Once we understood DNA
we could modify it
Curing genetically inherited
diseases in humans
Making mosquitoes extinct.
Increases rich/poor genetic
divide through designer genes
Fears around GMO food
safety (unwarranted accordingAnimalTesting Considered unethical to test
on humans
Fewer humans harmed in
scientiﬁc experiments
Unethical
ICTs Result of computer sciences ICTs have changed our lives in
terms of how we conduct
commerce, communicate and
learn
Espionage via back doors in
software for autocratic or
oligarchic states; no more
privacy (1984)

38.
ETHICS AND SCIENCE
“My other suggestion is in an attempt to solve the problem of
irresponsible people and especially those who are poorly
endowed genetically having large numbers of unnecessary
children. Because of their irresponsibility, it seems to me that for
them, sterilization is the only answer and I would do this by
bribery.” (Francis Crick).

39.
• Cultural imperialism
• If our science is true,
and yours is false, can
we impose it on you?
• How about testing
Muthi for efﬁcacy in
an RCT?
ETHICS AND SCIENCE

41.
ETHICS AND SCIENCE
• Objectivity vs Cultural Relativity
• Good reason to defend objectivity #2. If a Nazi
defends eugenics on the basis of racialism*, we can
claim that there is no scientiﬁc objectivity to the
doctrine (racialism), and therefore it ought to be
discarded.